Continuous rolling mill

ABSTRACT

CONTINUOUS ROLLING MILL COMPRISING A SERIES OF ROLLING STANDS, HAVING ROLLERS MOUNTED IN CANTILEVERED FASHION AND WITH AXES IN SUCCESSIVE STANDS MUTUALLY ORTHOGONAL, EACH STAND COMPRISING IN ADDITION MEANS FOR ADJUSTING THE WORKING DISTANCE BETWEEN THE SURFACES OF THE ROLLERS AND MEANS FOR   REGULATING THE AZIAL TRANSLATION OF THE ROLLERS WITH RESPECT TO THE ROLLING LINE.

United States Patent [72] lnventors Umberto Plgni; [56] References Cited s Cmllwu, Italy UNITED STATES PATENTS li zg' g 1,922,380 8/1933 Lucas 72 234x ii 5 d J ml 2,942,506 6/1960 Merting m1. 72/234 l l i 3,382,697 5/1968 Neumann 72/226 173] Asslgnee Ponunr Farrel S.p.A.Castellan 3,468,151 9/1969 Diolot 72/234 3,477,268 11/1969 Schoffmann 72/234 {32] Pnonty Sept. 30,1968 I [33] m Primary ExammerM1lton S. Mehr [3 l g 4 3 Att0rney-B. Edward Shlesinger [54] CONTINUOUS ROLLING MILL 8Claims6mawm8 Fla, ABSTRACT: Continuous rolling mill comprising a series of [52] US. Cl 72/234, rolling stands, having rollers mounted in cantilevered fashion 72/249 and with axes in successive stands mutually orthogonal, each [51 1 Int. Cl B21b 13/08, stand comprising in addition means for adjusting the working B2lb 35/00 distance between the surfaces of the rollers and means for [50] Field of Search 72/234, regulating the axial translation of the rollers with respect to 237, 248, 249, 238, 226 the rolling line.

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ATTORNEY PATENTED M28 19?! 587277 sum 3 or 3 I INVENTORS 57 v 31 32 2 g 60 BY W ' J ATTORNEY CONTINUOUS ROLLING MILL This invention relates to the continuous rolling of bars, rode and the like, and in particular relates to a continuous rolling mill which substantially eliminates torsion of the material being worked during its passage from one rolling stand to the other. It is well known that in the rolling of rods and bars in finishing rolling mills the reduction comes about by means of passage in successive rolling stands. The sections of the bars being rolled usually have two axes of symmetry, one parallel to the generating lines of the rollers and oneperpendicular to these. The dimensions of the section with respect to these two axes can be either equal or different. In this latter case the section leaving the rollers has its major axis parallel to the generating lines of the rollers. The section of the bars being rolled must arrive at successive pairs of rollers having turned through 90, so that the major axis of the said section is orthogonal to the axes of the rollers of the stand immediately succeeding. v i

It is clear that in this way the material being worked is subjected to torsion stresses which render its fitting between the rollers difficult.

Another drawback of normal continuous rolling mills consists of the complexity of construction and assembly of the stands, because of which the operations of maintenance and substitution, particularly for the rollers, are long and laborious with the consequent economic disadvantages resulting from long periods of down time of the plant.

This invention eliminates these and other drawbacks and disadvantages by providing a continuous rolling millwhich includes a plurality of rolling stands, in which the lying axes of the rollers of any two successive stands are mutually orthogonal and in each stand the rollers are mounted cantilevered on a support common to theentire rolling mill, and in which in addition each stand includes a device for adjusting the working distance between the surfaces of the rollers, and a device for the axial translation of the rollers with respect to the rolling line, the rolling mill in addition including a device for adjusting the rotational velocity of the rollers located between successive rolling stands.

The principal advantage of this invention consists, as previ ously mentioned, in the fact that the material being rolled is no longer subject to torsion during its passage from one rolling stand to the successive one and in this manner the fitting between the rollers is greatly facilitated.

Another advantage worth noting is that the assembly and disassembly of the rollers is rapid and easy.

. A further advantage which will become clear in the follow ing description consists of the system for transmission of motion to both rollers of each stand which also permits their reciprocal drawing near and drawing apart, according to the thickness of the material being rolled.

A still further advantage is that of the interpositioning between successive rolling stands of a differential device which allows the velocity of the downstream rollers to be varied between certain limits, if desired.

Finally a still further advantage not to be ignored derives from the particular constitution of the rollers and of the device for effecting the axial translation with respect to the rolling line, so allowing a greater exploitation of the working surface of the rollers themselves.

Further, aspects, objects and advantages of this invention will be clearer from the description which follows of a preferred embodiment, shown by way of example with reference to the accompanying drawing, in which:

FIG. I is a general diagrammatic view of the continuous rolling mill according to this invention;

FIG. 2 is a partially sectional view of a detail of the device for locking the rollers on the shaft;

FIG. 3 is a partially sectional detailed view of the device for adjusting the working distance between the rollers of a stand;

FIG. 4 is a partial view through the line IV-IV of FIG. 3;

FIG. 5 is a sectional view of the device for varying the velocity between two successive rolling stands and FIG. 6 is a partially sectional view of the device for axially adjusting the rollers with respect to the rolling line.

Considering first of all FIG. I, a continuous rolling mill is shown which includes a single base ,plate 10, on which rolling stands are assembled with their axes alternatively horizontal II and vertical ]2. For driving the entire rolling mill a motor 13 is provided coupled to a reduction gear I4, the exit shaft 15 of which rotates all the rollers 18 of the rolling stands I] and 12. Disengaging couplings 16 are able to disconnect the pair of stands I] and 12 according to the requirements of the rolling operation.

As can be clearly seen, the rolling line 17 alternatively meets rolling stands having rollers with their axes horizontal II and vertical 12.

These rollers 18 consist, as shown in FIG. 2, of a central shaft 19 on which an envelope is mounted having its external surface grooved 21, and which, in the coupling in the working position between two rollers 18 in a rolling stand, give rise to a series of rolling channels. i

For the anchoring of the envelope 20 on the shaft 19 a locking system is provided which includes a conical sleeve 22 forced by the key 23 between the shaft 19 and the envelope 20 by means of the screw 24.

It is to be noted that it is possible to carry out the disassembly and/or the substitution of the envelope, 20, by simply extracting the screw 24 and introducing in its place a similar screw but which has no thread in the part which penetrates the body of the shaft 19. In particular this allows envelopes to be economically manufactured of steel, cast iron or sintered carbides suitable for rolling.

Considering now the FIGS. 1, 3 and 4 it is seen that the rollers of a rolling stand are assembled cantilevered on two parallel shafts [9, which in their turn are supported by frames 27 and 28. At one end each shaft 19 carries a gear wheel, 29 and 30 respectively, engaged with a gear wheel, 31 and 32 respectively, these latter two gear wheels being mutually engaged.

The two frames 27 and 28 are pinned so that they rotate around the axes 33 and 34 of the gears 31 and 32 by means of two levers 35 and 36, whose free ends 37 and 38 are fixed to a spring 39, which tends to force the two rollers 18 away from each other.

The two supporting frames 27 and 28 are connected by a screw 40, turned by a wheel 41, the rotation of which brings about a mutual drawing near or drawing apart of the frames 27 and 28 according to the direction of threading of the screw 40 in the respective holes in the said frames. In order to cause the two shafts 19 to rotate a transmission system consisting of gear wheel 42 and pinion 57 is provided, its shaft being driven by means of a suitable transmission means (not shown) from the principal motor shaft 15. The gear wheel 42 is engaged with the gear 31, so that the motion is transmitted through the coupling between the gear wheels 32 and 29 for the upper shaft 19 and the gear wheels 3l and 30 for the lower shaft 19 respectively, for driving the rollers 18.

Considering now FIG. 5, a differential mechanism indicated overall with the number 43 is shown, including a spider frame 44, which is inserted between two successive stands, n and n +l. Inside the framework 44 two planet wheels 45 and 46 are mounted, which idle on the shafts 47 and 48 and engage with the gear wheels 49 and 50 which are keyed rigidly onto the shafts SI and 52 respectively, these shafts arranged so that they transmit motion to the said stands n and n +l.

A gearwheel 53 is rigidly fixed to the spider frame 24 and is engaged with a pinion 54 and is driven by means ofa variable velocity motor 56 through the shaft 55.

Let: 0),, be the velocity of rotation of the shaft 51 (proportional to the velocity of the rollers of the stand n m be the velocity of the shaft 52 (proportional to the velocity of the rollers of the stand n +1 Qbe the velocity of rotation of the spider frame 44, then for an epicylic rotation of the type shown in the HQ, we have the well known relationship;

From this it is seen that, leaving out the directions of rotation, if

=0, then m If on the other hand the frame 44 is made to rotate with velocity Owe have from which if Q. varies then m, H varies.

In this way a certain flexibility in the gauging and in the diameters of the rollers is possible.

At this point it is appropriate to emphasize the fact that the rollers 18 are mounted cantilevered or in other words anchored to the rest of the machine at only one end on their respective shaft, because of which the operations of maintenance and/or repair are considerably simplified and accelerated.

Considering finally FIG. 6, this shows in detail the device for actually adjusting the rollers, fixed in this case to a stand of rollers 18 having their axes vertical.

As can be clearly seen, the mechanism for axially adjusting the rollers is enclosed in a box 58 in which a supporting framework 59 is housed, in which the shafts 19 of the rollers 18 have their seats.

The framework 59 is mounted on a stanchion 60 so as to be able to slide on it under the action ofa motor 61 which by way of a right angled transmission system can rotate the driving screw 69 which is coupled by means of a thread to the framework 59. This latter also carries a rod 63 to which magnetic blocks 64 are fixed, which activate a magnetic head 65 which transmits an electrical impulse through the conductors 66 to the amplifier 67, which in its turn provide for the instantaneous stopping of the motor 61.

It is clear that the distance between two successive magnetic blocks 64 corresponds exactly to the distance between the flats of two axially successive grooves on the rollers 18. The movement of the rolling channel can either be controlled manually by activating the motor 61 or by suitable and wellknown technical means for programming the channel movements at preestablished intervals during the operation cycle. The invention as thus conceived may be subject to numerous variations and modifications within the scope of the appended claims.

We claim:

1. A continuous rolling mill including a plurality of rolling stands, each stand having a plurality of rollers rotatably mounted thereon, the axes of the rollers of any two successive stands being mutually orthogonal and, the rollers in any stand being mounted cantilevered, each stand including a device for adjusting the working distance between the surfaces of the rollers, a device for adjusting axial translation of the rollers with respect to the rolling line, and a differential device disposed between successive rolling stands for adjusting the velocity of rotation of the rollers.

2. A rolling mill as claimed in claim 1, in which in each stand the rollers are supported cantilevered by a framework mounted on a base plate common to the entire rolling mill, each roller including a central shaft on which a lining of material forming a suitable external rolling surface is mounted, said external surface being furnished with grooves which work in cooperation with equal and opposite grooves of the second roller of the stand, said lining being fixed to said central shaft by means which permit the disassembly and substitution ofit.

3. A rolling mill as claimed in claim 2, in which said means for fixing said lining to said central shaft include a conical sleeve, having its minor diameter equal to the diameter of said shaft, a key for locking the sleeve in the wedged position between the central shaft and the external lining and a screw for lockin the key. I

A ro ling mill as claimed in claim 1, in which in each stand the central shafts of the rollers contain at their extremity a gear wheel which is engaged with one of a pair of transmission gear wheels, which in their turn are mutually engaged, one of these transmission gear wheels being in addition engaged with a driving gear wheel driven by a motor, and in which each central shaft and its corresponding transmission gear wheel are rigidly fixed to a lever, having its fulcrum at the point of instantaneous engagement between said transmission gear wheels, said lever having one end fixed to resilient means and the second end fixed to a framework, the reciprocal distance between the two second ends of said levers, or rather between the two frameworks, being adjustable.

5. A rolling mill as claimed in claim 4, in which said resilient means consist of a spring whose two ends are linked to said two first ends of said levers and said means of adjustment comprise a screw, turned by a hand wheel and engaged with corresponding threaded holes in said frameworks fixed to said second ends of said levers, the threads in said holes and in the corresponding parts of said screw being in the opposite direction.

6. A rolling mill as claimed in claim 1, in which said differential device includes a box which is drivenby means of a motor at the desired velocity, two conical planet gear wheels being provided in said box which idle on their respective hubs and each engaged at with two gear wheels rigidly fixed to two motor shafts leaving the preceding stand and entering the following stand respectively, said motor shafts being rigidly fixed to said box.

7. A rolling mill as claimed in claim 1, in which in each stand said central shafts of the rollers are mounted cantilevered on a single framework movable along an axis perpendicular to the rolling line, said framework including means for arresting its movement when it has been moved through a distance equal to that between the centerlines of two successive grooves on the surface of the rollers.

8. A rolling mill as claimed in claim 7, in which a motor is provided for the movement of said framework, and said means for arresting its operation are controlled by an electric signal emitted from a magnetic head activated by magnetic blocks located on a rod rigidly fixed to said framework, said magnetic blocks being distanced along said rod by a distance equal to said distance between the centerlines of the said successive grooves. 

